A conventional puller device, such as one disclosed in U.S. publication No. 2008/0224109 includes a pulling assembly hinged with a plurality of hook claws and a movable frame to hold the pulling assembly. Through the movable frame the pulling assembly can be moved up and down in parallel or inclined upwards and downwards to make fine tuned adjustment to facilitate disassembly of a working piece.
The aforesaid pulling assembly includes three sets of opposing grippers to securely grip a targeted wheel to avoid dropping. However, in the event that the puller device operation has to be performed in a smaller space and the three sets of grippers cannot be deployed at the same time, and merely two grippers can be used for pulling, another set of puller device with only two grippers must be deployed. This causes more investments of the equipments. Moreover, the grippers of the aforesaid puller device merely hinged on the body thereof without additional anchoring facilities, safety deficiency becomes a big concern. In addition, its lifting facility does not have extra support. In the event that mechanical disorder takes place or malfunction occurred to the hydraulic equipment, an unpredictable sudden drop could happen. This not only interrupts puller device operation and causes damage of machineries, could even risk operator's safety.